2 methods to hook up a powered woofer >

Turbota

Folks ... You really have to excuse my ignorance, but could you look at these 2 diagrams. I believe either one of them will hook up a powered subwoofer to a 2 channel audio system that consists of a pair of rear, and a pair of front speakers.

One basically just has you sending both the left and right rear speaker channels of the pre-amp to the left and right input terminals of the woofer. Then attaching the wires from the output terminals of that woofer to the left and right rear speakers.

The other diagram has does the same thing as the first one I discribed: Sending both the left and right rear speaker channels of the pre-amp to the left and right input terminals of the woofer.

>> But, instead of the rear speaker wires coming from the output terminals of the sub, they are attached to the pre-amp just like the subwoofer.

Would both these hookups acomplish the same thing?

Turbota

Here is the first diagram >

Turbota

Here is the second >

rs159

In the first one, the crossover on the sub would keep deep bass from getting to the rears...The rears are happy, the sub handles all the bass, everything is good.......

Now in the second one, the rears get a full range signal...they could get too much deep bass and go *kaput*...

(lets be pc)...imho, in my experience, in my system, and correct me if im wrong :rolleyes: its better to do it the first way...unless you have serious rears, or the crossover in the sub is really, really cheap.

gatemplin

I agree with rs159, the first way looks better. Great diagrams by the way, very helpful.

Tour2ma

In your graphics you're showing "pre-amp" out to speakers, I think you mean "amp". That said...

Only questions I have is what "load" the Rava appears as to the amp. I don't beleive it's an issue, but I've not thought about it before. There are few concerns with your Spec 4 handling your 70's and 38's (?) in parallel, a 4-ohm load, but in the 2nd option the sub input is also in parallel...

The above just adds to the sentiments already expressed, that option 1 looks better for you. It's not a set up we are used to seeing, but since the signal is the same to both pairs of speakers, it doesn't matter which output feeds the sub.

Also using the sub in the path to one pair also reduces the number of bass producers, thus simplifying bass management, i.e., wave reinforcement and cancelation.

Turbota

"In your graphics you're showing "pre-amp" out to speakers, I think you mean "amp". That said..."

On the Pioneer pre-amp and power-amp, all the connections to the speakers come off the pre-amp. The only connections for speaker wire on the power-amp is the 4 terminals that connect to the pre-amp. They are:

+ right speakers
- right speakers
+ left speakers
- left speakers

In fact, the pic below is the back of the pre-amp. You see 8 spring clip terminals for 4 speakers (lower center). The small block of spring clip terminals on the far lower left are the ones I show above that just connect to the power-amp



Ron,

gatemplin

I dont believe that the Rava provides a load for the amp. It just filters out the low frequencies and passes along the rest to the mains. The signal is then amplified by the sub.

Tour2ma

Can't tell what I am looking at in your pic, but your description is a tad unusual to say the least...

A major point of separates is to keep the amplified signal away from the line level pre-amp operation. Why would Pioneer route the amplifed signal back to the Pre-amp?

Edit... OK, coming back for speaker selection control I'm guessing... Still is an unusual approach.

And yes, agree that the Rava likely presents no load, but never thought about wiring a powered sub in parallel before...

gatemplin

Good question Tour, I was thinking the same. As to whether it can handle a 4ohm load, I dont this either but it sure looks like it can.

Turbota

Well, here is a pic of the back of a Pioneer Spec 2 [power-amp]

I have a Spec 4 [power-amp], but the back is the same.

As you can see, the 4 speaker terminals on the back hook up to the 4 terminals on the lower left side of the Spec 1 pre-amp (as the pic in my previous post shows).

This is a very poor pic, but you can see the 4 terminals:

Turbota

BTW, I called the Polk Audio 'tech info' line and talked to someone. I explained this whole deal to them, and they told me I could hook up this system either way and it would make no difference.

Even though I am "Stereo Stupid", I think it may make a difference. ****, I am a pilot, so what do I know about HiFi!

Anyway, I trust the knowledgeable folks on this board to give me the right info.

And, again .... I do really appreciate all your [valuable] input

Ron,

rs159

It does make a difference. Trust me.

Like I said before, one option, the rears get bass....the second, they get less bass...if that doesn't make it different then my name is gaye male.

Turbota

BTW, below is the specs on that Rava Sub. I believe it is a 8 ohm speaker just like the Polk RTi70 and 38s I just ordered.
_________________________________________

Size: 18" wide, 18" deep, 18" tall (including 2" tall pedestal)

Weight: 65 pounds, net

Driver: Single 12" [Shiva] high-displacement driver

Alignment: Sealed Q=0.67 low Q design

Power: 250W RMS (2 dB headroom); 115/230 VAC inputs

Bandwidth: +0/-3 dB: 27 Hz to crossover point

Crossover: 40 Hz to 160 Hz

Phase Fully variable from 0 to 180 degrees

Output: 100 dB SPL above 25 Hz, anechoic
105 dB SPL above 30 Hz, anechoic

S/N: 100 dB at full rated output

THD: 3% at 95 dB SPL output, from 25 Hz to 160 Hz

Turbota

rs159 ...

Well, I appreciate your input.

You think both the left and right (rear in my case) speaker wires should come directly to from the pre-amp ... then to the input of the powered subwoofer. Then, out of the 'output" of the subwoofer, directly to both the right and left rear speakers.

Of course, the [front] RTi70 speakers just get wired up as usual ... From the [front] pre-amp output terminals to the left and right fronts speakers as usual. The subwoofer don't effect this at all ....

Thanks,

gatemplin

Rs159 is right, the first way is best, no bass to the 38's. Also it makes no difference what the subs impedence value is, it has its own amp. The speaker wire is just sending a voltage signal to the sub, and the sub amp provides the current. Also, enough pictures already, they are making me jealous!:D

Edit: Yes, from pre to sub in. sub out to 38s. It does make a difference, the polk person probably meant that it will work either way, true but the way rs159 descibed is best.

Turbota

Thanks everyody.

I am hooking it up as per the first example like everyone suggests.

Turbota

.